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Nanoscale copper powder has been produced using such an energetic method as the electric explosion of metallic wire (“EEW” process) in an inert gas. The crystalline structure of nanoparticles has been characterized by HRTEM and particle size distribution has been measured. The nanopowder has been added to motor oil and friction coefficient measured to compare with that of pure oil. SEM characterization of the worn surfaces and X-ray microanalysis have been performed to reveal both changes in topology of the worn surfaces and traces of copper.

Spray combustion tests of gaseous oxygen atomized sprays of RP-1 gel propellants with ultra-fine aluminum particles were performed in a rocket engine. The addition of aluminum particles to RP-1 gel propellants has the potential to significantly increase the heat of reaction over neat RP-1 due to the high volumetric energy release of the aluminum. Alex® powders, which have an average particle size of 100 nanometers, are formed by exploding aluminum wires. The use of these nano-sized particles can, theoretically, lead to more complete combustion, and thus, lead to performance increases such as higher flame temperature, increased specific impulse, and greater c* combustion efficiency. The engine operating conditions were as follows: chamber pressures ranging from 1-2.8 MPa (150-400 psia); gel propellant mass flow rates ranging from 8-40 g/s; gaseous oxygen mass flow rates ranging from 14-60 g/s; and oxygen-tofuel (O/F) ratios ranging from 0.5-5.0. The percentage of Alex® particles in the RP-1 gel propellants ranged from 0-55% by weight. The c* combustion efficiency was found to range from 60-99%. Results show that among the formulations, the RP-1 gel propellant with 5% of Alex® powders by weight appears to be the best in terms of range of c* efficiencies and the least amount of data scatter.